<html>
<head>
<meta charset="utf-8" />
<title>js输入对话框</title>
</head>
<body>
<script language="javascript">
age = prompt("请输入你的年龄:","20");
if (age != null){
alert("你今年" + age +"岁了!");
}else{
alert("你按了[取消]按钮");
}
//-->
</script>
</body>
</html>